package com.alinesno.infra.common.core.encrypt.encryptor;

import cn.hutool.core.util.StrUtil;
import cn.hutool.crypto.SmUtil;
import cn.hutool.crypto.symmetric.SM4;
import com.alinesno.infra.common.core.constants.AlgorithmType;
import com.alinesno.infra.common.core.constants.EncodeType;
import com.alinesno.infra.common.core.encrypt.EncryptContext;

import java.nio.charset.StandardCharsets;

/**
 * sm4算法实现
 *
 * @author 老马
 * @version 4.6.0
 */
public class Sm4Encryptor extends AbstractEncryptor {

	private final SM4 sm4;

	public Sm4Encryptor(EncryptContext context) {
		super(context);
		String password = context.getPassword();
		if (StrUtil.isBlank(password)) {
			throw new IllegalArgumentException("SM4没有获得秘钥信息");
		}
		// sm4算法的秘钥要求是16位长度
		if (16 != password.length()) {
			throw new IllegalArgumentException("SM4秘钥长度应该为16位，实际为" + password.length() + "位");
		}
		this.sm4 = SmUtil.sm4(password.getBytes(StandardCharsets.UTF_8));
	}

	/**
	 * 获得当前算法
	 */
	@Override
	public AlgorithmType algorithm() {
		return AlgorithmType.SM4;
	}

	/**
	 * 加密
	 *
	 * @param value      待加密字符串
	 * @param encodeType 加密后的编码格式
	 */
	@Override
	public String encrypt(String value, EncodeType encodeType) {
		if (encodeType == EncodeType.HEX) {
			return sm4.encryptHex(value);
		} else {
			return sm4.encryptBase64(value);
		}
	}

	/**
	 * 解密
	 *
	 * @param value 待加密字符串
	 */
	@Override
	public String decrypt(String value) {
		return this.sm4.decryptStr(value);
	}
}
